Using ACE as a swaybar disconnect

[66rover99]

>The stock LR radius arm will bind before the swaybar stops articulation. I tested different sway bar spring rates on the stock setup. With the springs removed, the radius arm binded at the axle mount before the swabar limited travel. With the springs installed, axle movement was limited by the spring before either the radius arm binded up or the swaybar limited travel.

lot's of experimenting going on with the coilover set-up...

Thanks, Mongo, for your answers. Should be interesting to watch your progress on this project. Have you got a thread going with updates as you go?

Only thing I'd disagree with you on is the radius arm binding, because D2s have their radius arms attachment hardware perpendicular to, rather than in line with, the radius arm, and can more or less rotate as far as the rest of the suspension allows.

I don't know whether there are limitations to the spring travel before the radius arms bind, or the swaybar binds, or shock travel for that matter. All I know is when I removed the sway bar on the front the travel became much more like that of a Defender or RR classic and the wheels were on the ground much more of the time.

Hmmm, guess I'm gonna have to consider extended brake flex hoses and ABS wiring too...

Dave

 

[Mongo]

yeah, there's thread going, but i haven't updated it lately (toy swap). I'll try an get some pictures going...

I thought that about the radius arms too, but without the springs, that's where it started to bind without the swaybar...

 

[kid4lyf]

How is this supposed to stop the hydraulic cylinder from moving? In this diagram the fluid is free to move from one end of the cylinder to the other.

The reason the cylinder will lock is hard to explain without a diagram (and I truly bring the suck to computer work) but here goes.
Picture a typical hyd cylinder halfway extended.
You have the rod sticking out one end, piston in the middle of the stroke.
The amount of fluid in the base side is higher than the rod side because the rod itself takes up internal volume.
So the total amount of fluid it takes to fill the cylinder, front and back, changes with every bit of movement.
For example, if the rod is fully extended the cylinder may take 1 gal to completely fill it. With it fully collapsed it may only take 1/2 gal (due to the rod taking up internal space). Halfway extended may take 3/4 gal...
IOW, every bit of cylinder movement forces the total volume of oil to change. If you stop oil from flowing in or out of the system you stop the cylinder from being able to move.
It's the same system a crane uses as a safety. They have a valve that locks the flow from both ports. That way, even if the internal seals fail the cylinder can't move.

 

[kid4lyf]

OK, how about version 2...?

View attachment 25583

Dave

Unneeded, see above post.

 

[kid4lyf]

lot's trial and error, while waiting for parts I tested different swaybar spring rates on the stock suspension (LR Radius arms, 3" RTE springs and 12" 360/80 vavling, charged with 275lbs of nitrogen,Blingstiens) so here's real world answers (seeing how that's the joke these day's...)...

1. It would seem to me the logic of long travel would be that the longer "levers" make it easier to twist/flex the bar to a much higher degree of articulation. Therefore wouldn't that be similar to just putting a smaller diameter sway bar on instead of the stock one?
>The ones I made have a 1.25 .188 wall sway bars. Bigger than stock. The control arms are actually shorter than stock because we moved the axle forward one inch. The "long travel" aspect is the arm that connects the control arm to the axle. I can adjust the amount of flex by changing the spring rate of the sway bar. It's not dialed in yet, but I can get different spring rate depending on the diameter of the tube used. I can even do solid tube, if need be.

2. Wouldn't a long travel bar therefore be less effective on-road than the stock bar?
> can be more effective, once again depending on the spring rate of the sway bar. It won't be a "limiting factor' just a "control factor"

3. My goal is articulation, not just travel. I can understand a long travel bar allowing further up-down movement, and weakening the swaybar's overall flex rate, but it still isn't going to allow flex nearly as well as having no swaybar connected at all.
>The stock LR radius arm will bind before the swaybar stops articulation. I tested different sway bar spring rates on the stock setup. With the springs removed, the radius arm binded at the axle mount before the swabar limited travel. With the springs installed, axle movement was limited by the spring before either the radius arm binded up or the swaybar limited travel.

lot's of experimenting going on with the coilover set-up...

After 4 linking the rear of my XJ and using Fox AirShox it was way too loose for comfort. Decent in rocks but scary on the road and with anything off camber?
Faggettaboddit.
I talked to the company who does flame hardening for me. They do a lot of race car work; axles, driveshafts, swaybars, etc.
They recommended AMS6418 steel for the main shaft. It wasn't easy to find but well worth it. They said in tests they could get 180 degrees of twist with full spring back after heat treating to a 48 RC.
3/4" dia completely got the rear of my 5500 lb XJ under control without losing any of the flex.
Here is a link if interested:
http://www.naxja.org/forum/showthread.php?t=93596

 

[flyfisher11]

This thread has gotten me thinking of the C-5 Galaxy which I am a flight engineer on. Anyway what you all are talking about in theory is exactly how our castor/powerback system works. If it can work on a loaded down C-5 at 769,000 pounds I think it will work on a disco. Here is how it works in a nutshell. First off we have 28 wheels and tires, four on the nose gear and four on each main gear respectively. There are four main gear just under the center of the fuselage. As we enter into a turn at aproximately twenty degrees on the nose we flip a switch on the center console that opens up valves on the aft main bogies allowing a run around of hydraulic fluid so that the gear can castor. Basically if you can picture it the fwd main gear are locked in place and move with the fuselage and the aft mains point outward freely allowing the big jet to "pivot" in a turn on the tarmac. As we come out of the turn we throw the castor switch to center which actuates two big actuators atop each rear bogie "powering back" the aft gear to center. When they get within 4 degrees of center the run around closes off creating a liquid lock keeping the aft gear centered. With that said basically all that keeps the gear centered on this beast is a liquid lock. This is a little off topic but I feel it is the same principle and might be relevant to those interested in hydraulicly controlled sway bars.

Cheers,

Mike

 

[66rover99]

Thanks Mike, now I can call my idea an aircraft engineered swaybar disconnect!

Kid4lyf, in one of your earlier posts, you suggested a second shutoff valve to compensate for wear down the road, so by using version 2, that supplies the second valve, doesn't it? but I'd still like to try it out with only one valve like version 1, just to confirm that the theory works...

Dave

 

[66rover99]

BTW Kid4lyf, very cool J**P.

Dave

 

[kid4lyf]

Thanks Mike, now I can call my idea an aircraft engineered swaybar disconnect!

Kid4lyf, in one of your earlier posts, you suggested a second shutoff valve to compensate for wear down the road, so by using version 2, that supplies the second valve, doesn't it? but I'd still like to try it out with only one valve like version 1, just to confirm that the theory works...

Dave

That was when I thought we were talking about two cylinders.
Version two really doesn't add anything. If the cylinder's seals wear, allowing it to bipass internally, shutting down one side won't help.
With version one, the only way the cylinder will move is if the valve goes bad. Even if the internal seals fail, it can't move.
The only possible way for it to move is if it leaks externally and there's virtually no way to compensate for that.
However, you'll be able to see if that's happening (if you can tell the difference between that oil leak and all the others ).

 

[66rover99]

Ha, oil leaks? You should see my series truck! It has a flow through oiling system ? you pour it in the top and it just flows right through.

Actually the Disco's been very good, with the only oil leak ever hitting the driveway being the hydraulic jack. Somehow it lost a seal and dumped its fluid, but it's been replaced. :bigok:

 

[66rover99]

Do you think this valve would work?



Specifically I was looking at item D on this list. What do you think, kid4lyf, would it do the job?

Dave

 

[kid4lyf]

Do you think this valve would work?

View attachment 25620

Specifically I was looking at item D on this list. What do you think, kid4lyf, would it do the job?

Dave

Go with what gives you the most flow, IOW, largest port size.
However, I'd be concerned with the low pressure rating.
Not sure how much force will be generated by a cornering Disco.
I'll see what I can find here.

 

[1meandisco]

good idea, but it seems that it would be a little pricy...disconnects can be had for 'bout 35 bucks in parts...

Any idea where you can get the quick disconnects?

 

[66rover99]

Any idea where you can get the quick disconnects?

Virtually all the Jeep performance places carry some form or another, which are resonably easy to adapt. The Expedition Exchange used to have some for Discovery I but I think they were removed from their catalog recently.

You might just want to search for Disconnect or skyjacker on a Jeep site and you're bound to come up with some samples.

Dave

 

[66rover99]

Go with what gives you the most flow, IOW, largest port size.
However, I'd be concerned with the low pressure rating.
Not sure how much force will be generated by a cornering Disco.
I'll see what I can find here.

OK, I went to the local farm hydraulics shop today and they recommended this one, which is rated at 3000 psi constant, and currently on sale for $89.



They suggested putting a plug in port 3 and it would act as required.

Also phone some local auto wreckers today, but have yet to find an ACE sway bar and reservoir. Anyone have a link to a good (cheap) Discovery wrecker?

Dave

 

[kid4lyf]

OK, I went to the local farm hydraulics shop today and they recommended this one, which is rated at 3000 psi constant, and currently on sale for $89.

View attachment 25639

They suggested putting a plug in port 3 and it would act as required.

Also phone some local auto wreckers today, but have yet to find an ACE sway bar and reservoir. Anyone have a link to a good (cheap) Discovery wrecker?

Dave

Found the fly in the ointment.
You have two choices in solenoid operated valves; spool, as in the one you show, or poppet.
A spool valve isn't a 100% sealing valve, it will leak down which takes it out of the running.
A poppet valve will not leak down, however, poppet valves are all directional, IOW, they shut flow in one direction while allowing flow in the other; also no good here.
The only choice here is a ball type valve, basically the same type of valve that shuts off the gas to your stove or oven, only built for hydraulic pressures.
Unfortunately, ball valves are all manual.
So, to make a long story slightly less long, The only way to do this is by mounting a ball valve and manually moving a lever to release the cylinder.
It's still a far cry from crawling under the truck to connect but no, not as cool as hitting a switch.
Two advantages, however, are price (about $20) and this would be pretty foolproof (one less electrical thing to go wrong).
Here is a link to one.
Go to their Fluid Components catalog and scroll down to page 23; 86 series Stainless Steel, 2000 psi, ball valves
http://www.valleyind.com/index.html

 

[66rover99]

I wondered about that when I was looking at the various valves, but my level of knowledge is pretty slim here. The supplier I looked at had a large number of manually activated ball valves which could easily be mounted under the hood (similar to those you've provided the lik to). Yes, foolproof, and yet you still don't have to crawl under the truck. Might be the way to go. How about a ball valve with a mechnical linkage to engage it in the cab? Or, plumb the whole thing to the cab. It's just extra hose...

Dave

 

[kid4lyf]

I wondered about that when I was looking at the various valves, but my level of knowledge is pretty slim here. The supplier I looked at had a large number of manually activated ball valves which could easily be mounted under the hood (similar to those you've provided the lik to). Yes, foolproof, and yet you still don't have to crawl under the truck. Might be the way to go. How about a ball valve with a mechnical linkage to engage it in the cab? Or, plumb the whole thing to the cab. It's just extra hose...

Dave

Hydraulic lines running into the cab.
Bad Idea Jeans

 

[Mongo]

send me a pm...

 

[66rover99]

I've got the parts!

A local indy shop that recently dismantled a wrecked Disco II saved me all the ACE parts, so I now have both front and rear bars, reservoir, pump and a ton of other bits.

So, once the weather warms up a bit, I'll start doing some real testing. I'm gonna use the pump as the basis for a hydraulic winch this year, so the original power steering reservoir will probably get used for that.

Thanks for all the input, guys.

Dave